Adam Clarke Bible Commentary

Give them sorrow of heart - They shall have a callous heart, covered with obstinacy, and thy execration. The former is their state, the latter their fate. This is the consequence of their hardening their hearts from thy fear. Blayney translates, "Thou wilt give with a hearty concordance thy curse unto them." That is, Thou wilt give it to them freely, and without reserve; intimating that God felt no longer any bowels of compassion for them. Formerly he inflicted punishments with reluctance, while there was any hope of amendment: but, in the instance before us, the case was so hopeless, that God acts according to the simple principle of vindictive justice. The prophet therefore considers them on the utmost verge of final reprobation: another plunge, and they are lost for ever.